


The Insolence of Nature

by gaslightgallows (hearts_blood)



Category: Crimson Peak (2015)
Genre: Accidental Voyeurism, Alternate Universe - Canon Divergence, Brother/Sister Incest, Cunnilingus, Explicit Sexual Content, F/F, F/M, Femslash, First Time, Late Night Conversations, Loss of Virginity, Masturbation, Vaginal Fingering, Wall Sex
Language: English
Status: Completed
Published: 2018-05-01
Updated: 2018-05-01
Packaged: 2019-04-30 12:35:56
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,765
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14497128
Author URL: https://archiveofourown.org/users/hearts_blood/pseuds/gaslightgallows
Summary: Lucille hates having Thomas's wife in the house... or so she thinks, at first.





	The Insolence of Nature

**Author's Note:**

> Written for hallsofvalhalla, for the prompt: “Nightmare” (Edith/Lucille). This took two friggin' months to write, which is about six weeks more than it ought to have taken. 
> 
> If you're over on Tumblr, please consider following me at [gaslightgallows.tumblr.com](http://gaslightgallows.tumblr.com) for more fic, reblogs about writing, and lots of randomness. Thank you for reading and especially for commenting. Comments are love. ♥

_Et le printemps et la verdure_  
_Ont tant humilié mon coeur,_  
_Que j'ai puni sur une fleur_  
_L'insolence de la Nature._  
_– Charles Baudelaire, “À Celle qui est trop gaie”_

* * *

For a moment, Lucille wasn’t sure what had woken her. She stared up in confusion, waiting for her eyes to adjust to the darkness of the attic bedroom, while she struggled with the heavy curtains of sleep trying to fall back over her eyes. Finally, she pushed them aside completely, and knew.

She had heard something. Something out of the ordinary.

Allerdale Hall was an old, old house, with a voice of its own that was not shy or quiet, and Lucille knew all of its sounds, all of its creaks and groans and sighs and wails, as she knew the sound of Thomas’s peaceful breathing as he slept beside her. As she knew the noises of pleasure that he always struggled not to make.

And what she heard now was not a sound that her house was accustomed to make.

Thomas was still very much asleep. He had always been a deep sleeper, for as long as Lucille had known him – the years in between, when they had been kept apart, neither of them had slept well. The years she had spent in the asylum still haunted Lucille as one endless waking nightmare. There had been no rest for her there, not while she was away from her brother and her birthright. That first night together, after their estranged father died and left not only the baronetcy but Lucille’s legal guardianship to Thomas, allowing him to free his older sister, had been the first decent night’s sleep either one of them had had in years.

Since then, Lucille had been very protective of her brother’s rest. But as she woke more fully, she felt one quick stab of annoyance at him, lying beside her so beautiful and innocent and unawares, when it was his wife making all that noise downstairs.

By rights, she ought to wake him. He had chosen the little blonde bitch, after all, over all of Lucille’s objections and attempts to steer him towards a more suitably biddable girl. Edith was too intelligent, too inquisitive, too young, and she was having trouble settling in, which unnerved Lucille. None of Thomas’s other brides had taken so much issue with the house. Or perhaps it was the house taking issue with the bride, as Lucille did. Eunice McMichael would have been better. Less pleasant to look at, perhaps, and with an alarmingly large family to inquire after her, when she inevitably went missing, and certainly not as rich...

And probably quieter.

The soft high whimper echoed through the house again. From another room came the disturbed, delicate flutter of wings, as the moths in the attic were agitated by the unusual vibrations.

Lucille grimaced, and sighed, and got out of bed. Something was bothering the child, probably a nightmare, and if Thomas would not do his duty by his chosen wife (however temporary), then it fell to Lucille to see what was the matter with her.

Ah, well. She was used to doing the dirty work around the house.

She floated over the threadbare carpets and dry, creaking boards of the upper floors and drifted silently down the staircases, her thin nightgown hanging off her shoulders and trailing behind her. The house breathed loud and cold as she moved through it, and its breath smelled of mildew and clay and fresh snow, with the acrid tangs of coal and grease from Thomas’s machine outside prickling underneath. The string of steady, broken noises from the room where Edith slept (really, it was meant to be Thomas’s room, but he never slept there, when they were alone) was louder now, more desperate.

Lucille stopped just outside the door, paused and listened for a moment, and then tried the doorknob. She half-expected to find it locked, but it was open, and she slipped inside.

And then she stopped short.

She had assumed that Edith was asleep, and caught in the throes of a nightmare, undoubtedly cooked up by her prodigious imagination, so she hadn’t bothered to knock.

Edith was emphatically _not_ asleep. And what Lucille saw, rather than her sister-in-law tossing and turning from a bad dream, was Edith splayed out in Thomas’s bed in the light from the fireplace, the coverlet and quilt and blanket kicked back, and the skirt of her voluminous nightgown hiked up around her waist, with her legs spread wide and her fingers working busily among the pale curls. The soft, harried little cries that had carried themselves to Lucille’s ears were Edith’s masturbatory sounds of pleasure, mingled with whimpers of Thomas’s name.

 _Oh,_ thought Lucille, with a certain amount of disgusted amusement.

Now she was rather glad Thomas hadn’t awoken. He was loyal to her, but Lucille had eyes. Edith was pretty, willing, and almost tangibly eager, and Thomas was very much a man, in his own way. His self-control was, politely, strained.

But she had entered the room so quietly that Edith, whose eyes were screwed shut and whose attention was elsewhere, did not notice Lucille’s presence. She simply carried on groping awkwardly at her cunt. “Thomas... yes, please, please...”

Lucille suddenly felt a hot and jealous rage shoot up her spine, and with it, an infernal desire to strike her beloved brother’s name from Edith’s mouth. The arrogant presumption of the nosy yellow-haired brat—! The impulse lingered but was overshadowed by a more respectable desire to turn and leave. She would return to Thomas in her own room, wake him up, and then fuck him until they were weary again. Thomas was _hers_ and she was his, and he was not allowed to forget that.

“Lucille... mmm... yes, Lucille, yes...”

 _...Oh,_ Lucille thought again.

Intrigued and aroused, and if she had been able to be honest with herself, more than a little confused, she crept quietly over to the butterfly chair by the fireplace and settled down to listen, and to think.

It was surprisingly... pleasant, listening to Edith. Thomas was a quiet lover by preference – it came from their childhood, when they _had_ to be quiet, and throughout his adolescence, while they were apart, the sounds of sex had always heralded punishment, either for himself or for someone else. So, even now, he kept quiet. Lucille would have preferred, perhaps, to claim the air of the house where they had suffered, to etch its exhalations with her gasping cries whenever Thomas made her come. But the sounds of pleasure upset him so...

Edith’s desperate gasps and moans were silken against Lucille’s ears, and set a velvety ache blooming below her navel. _Such a pity..._ She was the only other woman Lucille had ever heard, and it sounded... mouth-watering.

_Such a pity that it had to be her._

The saddest part of this whole business, Lucille reflected, sliding a hand under her nightdress and stroking her fingers lazily through her rapidly-soaking folds, was that she had liked Edith, at the beginning. As much of an irritant and an interloper in their sanctuary as she found Edith now, when she first met the girl, she had felt an odd, awkward affinity for odd little Miss Cushing, who clearly fitted so awkwardly into the world around her. Lucille understood something of that. Of moving through an existence that was so awfully different from the one that nature had intended her for. And she had felt for Edith, at first, an uneasy impulse to protect her, to keep her safe.

To keep her, as she kept Thomas.

And she had tried to steer him clear of her, for all their sakes, to keep his attention focused on their intended target and away from this girl made of sunlight and silk and soft butterflies’ wings, who could never belong in their world and who did not deserve to be snuffed out like a feeble candle in the presence of their darkness.

But Thomas had gone his own way. He had made Edith Cushing love him – made her desire him—

“Oh, Thomas, please, _please!_ ”

—married her and brought her home to the house where had had been gotten and whelped and raised, all of it in pain and tears.

“Lucille, oh, _yes_... oh, _yes_ , oh God!”

She had no idea, of course. Poor innocent doomed Edith, so young and eager and bright, with her head full of ghosts and romance. She couldn’t have known that nothing good could ever come to her from this house.

Lucille’s fingers worked harder at her clit, and forced to be silent lest Edith realize she was there, she tried to imagine Thomas kneeling on the floor at her feet, as he had often done before, his hands on her thighs and his face buried in her cunt, licking and sucking as though she would spill out the waters of eternal life when she came.

But all she felt were her own fingers, and all she heard was Edith.

Damn Edith. Damn her!

Edith, with her foul American accent and her daffodil-coloured clothes and her infuriating bright youthful garishness. It was more than enough to make Lucille hate her. She _wanted_ to hate her, or to at least feel the same dull inevitable indifference that she tried to cultivate towards all of Thomas's wives, though it never lasted. No, cool good breeding and polite indifference were not lessons Lucille had imbibed in the nursery, so they could never be fixed in her character. She had been raised to skulk in shadows and to take what was hers, even if it meant tearing it from another’s still-beating chest. And all the bland and deadly courtesies of the aristocracy that her brother wore so effortlessly would never be anything but an ill-fitting mask to her.

She hated, and loved, with equal fire, and if they were the fires of Hell, then so be it.

She wanted to hate Edith, and could not. Because she was like Thomas. She _was_ Thomas’s.

And what was Thomas’s... was hers.

A sharp, high cry, not stifled quickly enough, erupted from the bed as Edith climaxed, and Lucille rode the wave of the sound, intolerably sweet, to her own silent release. And for a few more precious seconds, they were only sisters-in-law, one sinking into her husband’s empty bed with vague guilt and regret, the other drifting pleasantly in a sea of warm, velvet-dark dreams.

It could only end one of two ways: Lucille could wait until Edith fell asleep, and silently return to Thomas’s side, and say nothing, or she could reveal herself, and see what came of it.

She could also kill the girl, but that seemed like such a waste now.

As she was pondering their fates, Lucille noticed the sudden appalled stillness of the room. Edith, she realized, was holding her breath.

“Thomas?”

Lucille smiled. She could feel the heat of the little virgin’s cheeks from where she sat. “Not quite,” she said, and stood, coming out of the shadow of the great chair. Edith turned as red as Lucille’s favorite dress and hurried to cover herself. “I didn’t mean to startle you, but... I heard you from upstairs, you see.”

“Oh,” said Edith. “I... oh.”

She looked as though she wanted nothing more than to disappear.

Lucille’s smile widened as delight and desire twisted in her belly. “I thought you were having some hideous nightmare, so I came to check on you. And then when I saw what you were about...” Edith’s mortified modesty forced her to look away, but then she glanced back under her lashes, her eyes darting furtively at Lucille, tracing the outline of her body that the fire made through Lucille’s inappropriately thin nightgown. She swallowed.

“How much did you hear?” Edith asked, after a breathless handful of seconds.

“Hmm.” Lucille crossed the space from the chair to the bed, and loomed over Edith like an apparition, touching her face with curious fingers. “Poor frustrated little bride. So it’s not just your pretty husband that you burn for. I wish I’d known that sooner. We might have worked something out before now.”

Poor embarrassed Edith, so flushed and flustered by the presence of a witness, and especially a witness who was not merely her husband's sister, but one of the very people she had been fantasizing about, at great length and volume.

But when Lucille sat down on the bed, threaded her fingers through Edith’s long yellow hair and drew her forward for a kiss, Edith did not spend even a single second prevaricating. She threw herself headlong into kissing back.

It was astonishing.

Thomas so disliked open-mouthed kissing and the feeling of another person’s saliva in his mouth. His kisses drove Lucille mad with ecstasy, but they were always only kisses for her lips and skin.

But Edith was all tongue and teeth and spit and hands clutching the back of Lucille’s head, the better to delve more deeply into her mouth, to explore and to consume. She was so aching to be touched that she was laying herself out to be devoured.

Well, if that was what she wanted...

“How much do you want me?” Lucille demanded between kisses that were just shy of drawing blood, they were so hungry. “Enough to let me touch you?”

“God, yes,” said Edith without thinking. Then, “But, Thomas... we shouldn’t.”

“Thomas is asleep, and we are not. And what women choose to do when their men are asleep, well.” Lucille laughed against Edith’s jawbone and moved her mouth to Edith’s throat, to suck hard kisses into her neck and hear her whimper. “Tell me, Edith: shall I touch you?”

“Yes. Yes, _please_ —”

“No need to beg, my dear.” _Not yet... no, not just yet..._ She slipped her hands, too broad and strong for gentility, under the hem of Edith’s ridiculous leg-o-mutton-sleeved nightdress and grasped handfuls of the lace and linen and pushed it up, up, exposing Edith’s smooth stomach and small smooth round breasts.

It was almost too much – Lucille disliked the nudity of the human body as much as Thomas abhorred the sounds of sex – but Edith was clawing at her nightdress, tugging it up over her head and throwing it away, so eager to be naked in front of her. It was obscene and delectable and Lucille wanted all of it. She indulged herself in an orgy of touch, exploring every inch that she could reach. She bent her head and licked a long, slow stripe from the curve of Edith’s hip bone all the way up to her clavicle, pausing to investigate one tight pebbled nipple with almost scientific fascination. She could touch herself however she pleased, but she couldn’t do this to herself...

She savored the sounds of Edith’s gasps, little sharp sipping breaths like she was tasting the air, and then she slid back down the pale body. “Spread your legs for me. Now,” when Edith had parted her creamy thighs wide, “spread your lips for me.”

She felt the girl’s body tremble, but resolutely, Edith’s fingers slid over her blonde curls and between her folds, revealing herself to another for the first time.

By law and custom, this should be Thomas’s privilege. He had, after all, been the one to marry her. But Lucille was the eldest, even if she had not been the heir, and they had always been a sharing pair. What was hers was Thomas’s, and what was Thomas’s, was hers.

It was how they had always survived.

So if Edith was Thomas’s wife – and Lucille was becoming more and more convinced, in the pit of her stomach and in the dark places of her brain, that he wanted to keep Edith as his wife – then it simply stood to reason that she should be Lucille’s wife as well.

And for once, the baronet was not going to have the first pluck.

“Have you done this before?” Edith asked, her voice surprisingly steady for someone who looked nearly catatonic with terrified desire.

 _Brave thing._ Lucille’s admiration for their new pet swelled. “I’ve not done it with another woman. But I’ve had it done to me... oh, many times.” And Thomas was a most accomplished practitioner of this art. She had learned along with him.

She rose up between Edith’s legs and bowed her head over the young woman’s cunt. At the first experimental pass of her tongue, Edith gasped as though the breath had been torn from her body.

Lucille smiled. Her sister-in-law was so painfully aroused that partaking too delicately would simply shatter her, and Lucille wanted to enjoy this. She set to laving the flat of her tongue firmly over Edith’s dripping entrance, using broad strokes to calm her string-tight nerves. Only when Edith relaxed enough to dare to stroke Lucille’s hair did she renew her own efforts to torment.

She stretched her arms up, finding Edith’s breasts and teasing the tight nipples, and wrapped her lips around Edith’s clit. She suckled gently at first, but as Edith’s breathing grew more shallow she sucked harder, finding a rhythm, and laughing deep in her throat when Edith’s hips bucked in time, until at last Edith had to catch her cries between her teeth.

Lucille dipped her tongue into Edith’s cleft, savoring the untouched taste of her, like spring.

“I’m very glad I got to you before Thomas did,” she said, conversationally. “You won’t taste or smell quite the same, after he’s had you. Oh, it will still be good. But it will take some getting used to.”

She slipped a finger into the shining wet flesh. Edith tensed. “Thomas,” she started.

“Believe me, my girl, Thomas won’t mind a bit. He’ll be thrilled that we’ve... become such good friends.”

“No, I mean... I’ve never had a lover before.” There was an added flush rising on her chest and cheeks that made Lucille want to swallow her whole.

“Oh, no, my dear, that’s nothing to worry about. He’d be petrified of hurting you. It’s better if I do it. Thomas isn’t the sort of man who cares for taking a woman’s virginity.”

Edith frowned. “How do you know?”

Lucille leaned forward to kiss her, and smirked viciously at Edith’s little cry as her fingers pressed deep into Edith’s cunt, breaching her. “He cried when he took mine.”

The shocking statement was entirely lost on Edith, who had thrown back her head in mingled pain and euphoria, as her need to be _touched_ and finally _fucked_ was satisfied after so long. Lucille lowered her mouth to Edith’s throat and then to her breasts, and curled her fingers inside the hot pulsing flesh, seeking, and finding.

She felt Edith’s hands clawing at her hair, the way Thomas’s did when she used her mouth on him, heard Edith’s gasping, high soft tones shifting into things that were harsher, more guttural, more, more—

Edith let out a hoarse, tearing scream, and then another and another. Her cunt convulsed around Lucille’s fingers, squeezing and pulling, and Lucille kept going, kept rubbing at that one hard smooth place, until Edith had to grip her wrist and beg her, “Stop, stop.”

Lucille hummed a little, rather pleased, and kissed her way up to Edith’s mouth. “Well? Was that to your liking?”

“Mm. Need to…” Edith slumped bonelessly against the pillows of Thomas’s bed. Lucille sat back on her thighs, a satisfied expression on her handsome face, with Edith’s arousal dripping from her hand like thick ropes of molten glass. She toyed with the idea of offering her fingers, to make Edith suck her own cum and learn her own flavour... Instead, she held Edith’s eyes, and lifted her hand to her mouth.

Edith’s eyes grew wide and dark at the sight. Her chest rose and fell faster, and before Lucille was quite finished, Edith sat up and reached for her sister-in-law, kissing her like a woman famished, starving, parched. “What did you mean?” she murmured, curling and uncurling her hands in Lucille’s nightgown, as a cat might. “About Thomas? When he...”

“When he took my virginity? Oh yes, he cried. He’s always been a sensitive soul. He was so aghast at the thought that he’d hurt me. You see, I got all the harshness in the family.” Lucille smiled a smile full of gentle superiority in the face of Edith’s shock. “It’s more common than you might think, you know. But you see, for the longest time, we were all we had. It felt natural. Of course, now _you’re_ here...”

The embers of her attempt at hatred flared briefly and then subsided in confusion. Edith was listening with a rapt, sympathetic air that almost amounted to tenderness. “Is that why Thomas won’t sleep with me? Because he’s afraid of hurting me?”

Lucille very nearly burst out laughing. Well, the girl certainly wasn’t _wrong_ , though she couldn’t know that the hurt Thomas feared was his sister’s wrath, not the momentary discomfort of his cock splitting his pretty wife’s cunt for the first time. “It’s nothing you’ll have to worry about anymore,” she said instead, her eyes twinkling maliciously. “And he’ll be very glad to know that we’ve... known each other. Oh yes,” she continued, when Edith would have protested, “we’ve always been share and share alike, Thomas and I.” She skimmed her palms up Eidth’s ribs and over her nipples.

Edith whined and tried to kiss Lucille again.

“Ah, my dear, I think that’s enough for tonight.”

Edith actually pouted. “Why?”

_Because I’m afraid that if we keep going, girl, I might actually devour you whole._

“Because it’s late. And I was not at all prepared for this turn of events. If I’d known I was going to be having my way with you tonight, my sweet, I would have brought my magician’s bag.” She almost giggled at Edith’s perplexed expression. “That’s what Thomas calls my collection of devices. I’ve all manner of pleasant things.”

“Devices like...?”

“Like lovely velvet-covered dildos to tease your clit, and thick leather ones to stretch you, and floggers for warming your backside so that you _feel_ it when you're fucked. Padded cuffs to chain you to the bed so you can’t move, and a harness that holds a dildo against a woman’s cunt so she can fuck like a man.” Lucille gripped Edith’s hips and ground against her, and smiled at Edith’s low guttural moan. “Thomas likes it when I wear the harness, especially with the leather. He does so love a thick cock up his backside.” She smirked at Edith’s thunderstruck expression and pushed her back until she was lying down. “At least when it’s a woman wielding it. But this is talk for another night.”

She offered to help Edith dress, but Edith demurred. “I think... I think I’ll do without it, tonight.”

So Lucille left her that way, debauched and spent, her limbs all awry, though the kiss they shared before Lucille slipped away was, oddly, almost chaste.

“Good night, Lucille,” said Edith, very softly.

All of a sudden, Lucille shivered, and she beat a hasty retreat into the corridor.

Her eyes needed a moment to adjust from the low red-gold light of the bedroom to the cool blue-black light of the open house, and as she crept towards the staircase, catching her breath as though she had been running, she saw a luminous figure, all white and anthracite, emerge from the shadows, bearing a candle.

Thomas.

“What have you done?” he demanded, his voice a low, dangerous burr in the pit of his throat, and in the flicker of the tiny flame, his eyes an otherworldly shade of blue. Lucille was reminded, of all things, of their beloved nurse Theresa’s old tales about changeling children. “I heard Edith scream. Lucille—” He grabbed her arm with his free hand. “What did you _do_ to her?”

“Nothing but exactly what she asked me to do,” Lucille retorted. In one breath she blew out the candle in his hand and knocked it to the ground, and then in the next breath she grabbed Thomas’s head in both hands and dragged his mouth down to hers. For a second or two, he was stiff in her embrace, until he tasted the unfamiliar flavour on her lips, and the instant he realized what it was, he snapped. He slammed Lucille up against the wall and plunged his tongue deep into her month, licking hungrily at the taste of Edith clinging to the inside.

A brutal thrill shuddered through Lucille. Thomas had _never_ kissed her like that before...

He could keep Edith, she decided, in a flash of clarity like lightning slashing through an oppressive summer night. If it meant that Thomas would kiss her like _that_ , then he could keep his toothsome little wife for as long as he pleased.

“It’s not fair,” he growled, cupping her jaw in his long fingers and pressing his thigh between her legs. She was dripping wet beneath her nightgown and ground her cunt down against his hard muscle. “It’s not _fair_.” This time, it was a moan. “She’s my wife, and I’ve barely laid a hand on her.” A bit of a whine entered his voice. “I’ve been so good, Lucille...”

“You can be so pathetic sometimes,” said Lucille, running her fingers fondly through his soft brown hair. “So you want her, do you?”

He froze. “I can control it,” he swore, resting his forehead against hers and catching his breath. “It’s nothing, you don’t need to—”

Lucille’s hand tightened in his hair, just tight enough. He winced slightly in pain as his cock twitched eagerly against her knee. “She wants you. Rather badly.” She leaned in to breathe her next words temptingly across his lips. “So badly that she cried out in her sleep with lusting for you, and woke me... in more ways than one.”

She ripped open the placket of his trousers; he caught his big hands under her thighs and bit at her mouth, and in one heady wet hard thrust he pushed his cock inside her.

The force of his fucking pounded Lucille against the wall, and she tangled her fingers into his wild dark hair and jerked his head up from her mouth so that she could see, in the moonlight streaming through the dilapidated roof, the eerie blue light in his eyes.

He was so beautiful when he was frustrated, like an angel, lit from within by righteous fury, and the beauty of his face and his hands and his movements drove her over into bliss.

When she tightened around him, Thomas let out one quick cry – all he would ever allow himself, and then buried his teeth in her shoulder. He rutted his hips against hers with a last animal-like thrust and spent himself so hard that she _felt_ his come.

She kissed him once more, her eyes dark with a hunger of her own, and her lips curved into a slow and wicked smile. “Go in. Have her. I doubt any of us will ever sleep through the night again, if you don’t. She’s delicious in her abominations,” Lucille added, nipping her brother’s lips briefly before pushing him away. “Go to her. Just like this. Let her suck my taste off of your cock and see how she likes it. Oh, and don’t worry about hurting your virginal little Edith. I know how squeamish you are about that sort of thing. I’ve taken care of all that for you.” When he didn’t move, she rolled her eyes and grabbed his arm. “Go, Thomas. Spend the night with your wife. Fuck her into the mattress, that’s what you both want.”

“And what do you want?” he asked uncertainly.

Lucille picked up the snuffed candle and plucked a match from the box in her brother’s pocket with which to light it, to see her way back to bed. The shadows from the candle cast caressing shadows onto her handsome face, making her look strangely impish. “To join you both tomorrow night.”

Still doubtful, he went, slipping into his bedroom only half-prepared for the sight of his wife sprawled on his bed, fucked out and blissful. Lucille lingered just long enough, listening to the indistinct low murmurs of their conversation, until she heard Thomas’s shocked, desperate, “Oh _God_ ,” and took herself back to bed. She so badly wanted to join them, but what was hers was Thomas’s, and it was his turn.

Tomorrow. For the first time in a very long time, Lucille found she looked forward to tomorrow.


End file.
